A smartcard is an example of an RFID device that has a transponder chip module (TCM) or an antenna module (AM) disposed in a card body (CB) or inlay substrate.
The antenna module (AM) or antenna chip module, which may be referred to as a transponder chip module (TCM) may generally comprise:                a module tape (MT) or chip carrier tape (CCT), more generally, simply a support “substrate”;        an RFID chip (CM, IC) which may be a bare, unpackaged silicon die or a chip module (a die with leadframe, interposer, carrier or the like), typically disposed on a “face-down side” or “bond side” or “chip side” (or surface) of the module tape (MT);                    the RFID chip may have an antenna integrated therein, but generally a module antenna (MA) is typically required to effect contactless communication between the RFID chip and another RFID device such as an external contactless reader;                        a module antenna (MA) or antenna structure (AS), typically disposed on the same face-down side of the module tape (MT) as the RFID chip (IC), and connected therewith, for implementing a contactless interface, such as ISO 14443 and NFC/ISO 15693 with a contactless reader or other RFID device.        
When operating in a contactless mode, a passive antenna module (AM) or transponder chip module (TCM) may be powered by RF from an external RFID reader, and may also communicate by RF with the external RFID reader.
A dual-interface antenna module (AM) or transponder chip module (TCM) may also have a contact pad array (CPA), typically comprising 6 or 8 contact pads (CP, or “ISO pads”) disposed on a “face-up side” or “contact side” (or surface) of the module tape (MT), for interfacing with a contact reader in a contact mode (ISO 7816). A connection bridge (CBR) may be disposed on the face-up side of the tape for effecting a connection between two components such as the module antenna and the RFID chip on the other face-down side of the module tape.
A conventional antenna module (AM) or transponder chip module (TCM) may be generally rectangular, having four sides, and measuring approximately 8.2 mm×10.8 mm for a 6-contact module and 11.8 mm×13.0 mm for an 8-contact module. As disclosed herein, a generally rectangular transponder chip module (TCM) may have a larger or smaller form factor than a conventional transponder chip module (TCM). Alternatively, the transponder chip module (TCM) may be round, elliptical, or other non-rectangular shape.
A module antenna (MA) may be disposed on the module tape (MT) for implementing a contactless interface, such as ISO 14443 and NFC/ISO 15693. Contact pads (CP) may be disposed on the module tape (MT) for implementing a contact interface, such as ISO 7816. The module antenna (MA) may be wire-wound, or etched, for example:                The module antenna (MA) may comprise several turns of wire, such as 50 μm diameter insulated wire. Reference may be made to U.S. Pat. No. 6,378,774 (2002, Toppan), for example FIGS. 12A, B thereof.        The module antenna (MA) may be a chemically-etched planar antenna (PA) structure. Reference may be made to U.S. Pat. No. 8,100,337 (2012, SPS), for example FIG. 3 thereof.        The module antenna (MA) may comprise a laser-etched planar antenna (PA) structure (LES). Reference may be made US 20140284386.        
A planar antenna (PA) structure, or simply “planar antenna (PA)”, whether chemically-etched (CES) or laser-etched (LES) is a type of antenna structure (AS) and may comprise a long conductive trace or track having two ends, in the form of a planar, rectangular spiral, disposed in an outer area of a module tape (MT), surrounding the RFID chip on the face-down side of the module tape. This will result in a number of traces or tracks (actually, one long spiraling trace or track), separated by spaces (actually, one long spiraling space). The track (or trace) width may be approximately 100 μm. The planar antenna may be fabricated on other than the module tape, such as on a separate substrate, and joined to the module tape.
A module antenna (MA) connected to an RFID chip (CM), typically on a substrate or module tape (MT), may be referred to as a “transponder chip module”, or simply as a “transponder”, or as a “module”. Reference may be made to US 20150136858, US 20140361086 and US 20150021403, all of which are incorporated in their entirely by reference herein, for examples of transponder chip modules (and coupling frames).
Metal Jewelry and the Like as “Payment Objects”
In the main, hereinafter, transponder chip modules (TCM) and the RFID devices such as payment objects incorporating the transponder chip modules may be passive devices, not having a battery and harvesting power from an external contactless reader (ISO 14443).
Metal jewelry would not normally be considered for payment objects operating at a frequency of 13.56 MHz, as the metal would attenuate the electromagnetic field being picked-up by the passive transponder device.
Transponders can be attached to metal surfaces, if the effects of the metal can be shielded which is usually achieved using magnetic materials, such as ferrite, and spacing the transponder at a distance off the surface of the metal. See, for example, U.S. Pat. No. 8,366,009. See also US 20090159657 (2009 Jun. 25; Chen et al.) which discloses a contactless integrated circuit card system. A shielding member could be a conductor in form of a sheet, plate, or foil, and could also be a soft magnetic member.
Some Patent References
US 20140292477 discloses a system and method is provided for the identification and authentication of precious metals and small jewelry. The system can include an embedded RFID tag, RFID tag reader and reader based unit (wired or wireless), and a basic tag information system for tag capture, look-up and display. The RFID tag can be embedded in absorbing dielectric medium inside epoxy in a tiny cavity placed in the metal or jewelry. A thin layer of epoxy placed over the tag can ensure that the tag will not be damaged from rubbing against skin, abrasion or chemicals while still allowing the desired electromagnetic properties (antenna and the circuitry performance). The RFID tag information can be transferred to a computer through the reader, and can be matched with preprogrammed information in a database.
US 20140260424 discloses an apparatus for conveniently and unobtrusively carrying a radio frequency identification (RFID) tag. A RFID tag is disposed within a channel defined by a jewelry piece and covered with a decorative element or cap. The RFID tag is a passive-, battery-assisted passive-, or active-type RFID tag.
US 20140102136 discloses an apparatus for conveniently and unobtrusively carrying a radio frequency identification (RFID) tag. A jewelry piece is operatively connected to a housing using a screw post and threaded slot. A radio frequency identification tag and buffer ring are disposed within the housing and enclosed by a cap.
US 20130332353 discloses systems and methods comprising RFID data acquisition technology which may be embedded in a fob or tag for use in completing financial transactions. This fob may a self-contained device which includes a transponder and which may be contained on any portable form factor and may comprise flexible circuitry. For instance, the fob may be housed in a wearable transaction instrument, such as a bracelet, ring, wrist band, retractable id, necklace, jewelry charm, lanyard, key ring fob, watch, band, pin, and/or the like. The fob is configured to be used in concert with an RFID reader device.
US 20060192674 discloses Jewelry/personal articles in the form of sets of items which may be sold in pairs or groups, each article of the group being provided with the RFID circuitry unique to that pair or group and an electrical display which will illuminate when two or more of the items of the group are in proximity to each other, but not requiring one to be in physical contact with another. In one embodiment the personal article comprises a heart necklace and a circular pendant, each provided with an electrical display such as a lamp and a normally open battery powered electrical circuit interconnected with the electrical display and uniquely coded RFID containing a tag and reader. Operation of the electrical display is initiated by bringing the two articles within proximity of each other and the uniquely coded RFID circuitry of the one item recognizes the matched uniquely coded RFID circuitry of another item of the same pair or group.